Pagoda SL Group

W113 Pagoda SL Group => W11x chassis cars => Topic started by: Todd on September 07, 2022, 01:48:07

Title: M129.980 Fuel Injection Linkage Pivot Bushing Replacement
Post by: Todd on September 07, 2022, 01:48:07
While I wait for my radiator to come back from the radiator repair shop, I'm replacing the worn out bushings in the fuel injection pivot linkage.  This linkage assembly bolts to the top of the intake manifold, and also houses the throttle return damper, and the power steering servo that increases engine idle speed, when steering during parking maneuvers.

There are 3 bushings.  One is nylon (64 in the diagram), part number: A1800720393   Two are bronze (252 in the diagram), part number: A1800720305   All 3 are available from the dealer.  The bronze bushings came from Germany, which took about a week for my local dealer to get.

The bronze bushings had to be pressed out and the new bushings pressed back in, which was easily accomplished with a vise.  They had to be reamed to fit the shafts on each pivot arm.  Once the pivot assembly was re-assembled and installed, the improvement in linkage "precision" of movement was very noticeable.  Definitely a job worth doing.

The bronze bushing is also used in the "bell crank" pivot, located below the exhaust manifold, on the side of the engine block.  So 3 of the bronze bushings are needed in order to do this job.
Title: Re: M129.980 Fuel Injection Linkage Pivot Bushing Replacement
Post by: Cees Klumper on September 07, 2022, 05:51:24
In addition, I have found that this preciseness of /play in the linkages can have a material effect on the fuel injection mixture settings. So it could be advisable to  (re-) do the linkage tour after addressing the various bushings.
Title: Re: M129.980 Fuel Injection Linkage Pivot Bushing Replacement
Post by: Todd on September 07, 2022, 15:32:58
Absolutely correct.  Plus, this isn't the only location that has wear, which creates play in the linkage and either poor timing between the throttle plate and the injection pump, or poor overall function/throw of the linkage.